Equation 11 · Part 5 · Radioactive Clocks: How Nuclear Physics Gave Evolution Its Time
Symbol e^λ t
What this part means
e^λ t is one of the signed contributions combined to compute the quantity on the left.
Its job in the formula
e^λ t is one of the signed contributions combined to compute the quantity on the left.
Full expression→Symbol e^λ t→Article meaning
The passage around this formula
The uranium-lead and argon-argon methods both need to know, or be able to ignore, how much daughter isotope was already present when the mineral formed. The isochron method, used most often with the rubidium-strontium and samarium-neodymium systems, solves this by measuring several minerals from the same rock, each of which crystallized from the same well-mixed magma at the same time and so began with the same strontium or neodymium isotopic composition, but which incorporated different amounts of the radioactive parent isotope depending on their individual chemistry. Plotting each mineral’s present-day ratio of radiogenic daughter to stable reference isotope against its ratio of parent to…
Learn the underlying idea
An exponent tells how a base is used in multiplication. In x³, x is the base and 3 is the exponent: x³ = x × x × x.
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Sources cited in the surrounding passage
These citations provide research context; check each source for the exact claim it supports.